Polishing-machine.



H. ROBINSON.

POLISHING MACHINE. APPLICATION FILED ocT. 14. 1914.

' Patentd June 6, 1916.

HENRY ROBINSON, OF BROOKLYN, NEW YORK.

POLISHING-MACHINE.

Specification of Letters Patent.

Patented June 6, 1916.

Application filed October 14, 1914. Serial No. 866,601.

To all whom it may concern:

Be it known that I, HENRY RoBINsoN, a citizen of the United States, residing at Brooklyn, in the State of New York, have invented certain new and useful Improvements in Polishing-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. 7 v

The present invention relates to an improvedmeans for firmly securingin-place the cushions employed in machines for polishing knives and the like, wherein the polishing wheels which carry such cushions are placed nvith their faces mutually inclined and virtually in contact with each other on one side. In machines of this character the polishing cushions, carried by the mutually inclined faces of the revolving wheels, are subjected to a considerable wearing action and to pressures exerted angularly with respect to the carrying wheels. On account of the peculiar stresses which have to be met by cushions of this character, the problem of suitably fastening and supporting them, while permitting them to be easily and rapidly replaced when worn, has been found to be a difiicult one. I

It is the principal advantage of my pres ent invention that it supplies a simple and convenient construction. which adequately solves this problem without increase of expense.

The accompanying drawing shows partly in plan and partly in section, my improved construction as applied to one preferred form of knife polishing machine.

The machine shown in the drawing comprises a frame-work 10, on opposite sides of which are mounted the two polishing wheels 11 and 12. These are inclined with respect to each other, as shown, and are supplied with annular polishing cushions 13 and 1 1. A spring 15 tends to press the wheel 11 toward the wheel 12, and the shafts of these wheels aregeared together in a well known manner (not shown) so as to revolve in the same direction, when the handle 16, or other motive means is used.

When the object to be polished, such as a knife, is introduced between the cushions 13 and 14, at their point of virtual contact, 17 such object resting upon the abutment or polishing cushion.

stop 18, the rapidly revolving cushions exert a rubbing action upon thesides thereof. The cushions are consequently subjected to a mutual pressure at right angles to the dotted line a-b inthe drawing, which pressure is inclined to the axes about which the wheels 11 and 12 revolve. The plane indicated by this line may be referred to as the plane of contact between the cushions.

The wheel 12' and cushionl are shown in sectlon in the drawing to illustrate the details of construction. The bearing or pressure-resisting face 18 of each wheel 11 and 12 is bent backward to conform to a portion of the surface of a flat cone having its apex in the axis of revolution of each wheel respectively, and these cones are so arranged that their elements opposite the line of contact ab are substantially parallel to said line and to each other.

The polishingcushion is preferably made in annular form, havinga resilient body 14, and a covering 19 of leather or other suitable material. The cushion as a whole has a fiat bottom conforming to the conical form of the pressure surface of the corresponding wheel, and in cross section the cushion is tapering to a contact surface 20, narrower than the base. forms to a cone, so placed that the elements assume a mutually parallel position when opposite the line of contact ab. The inner and outer surfaces of the cushion preferably also conform to conical surfaces, 21.1". though, it is within the invention to make the outer surface practically cylindrical, with elements parallel with the axis of revolution of the corresponding wheel carrying the cushion. These side surfaces are grippedbetween an external flange 21 on the wheel and an opposing surface forming the periphery of a securing disk 22. This securing disk has a flat surface 23 adapted to fit against a similar surface at the center of the wheel, and the periphery of the disk is conical in form to fit the inner wall of the annular It is clear that, when the disk 22 is fastened in place, as by the bolt 24, an annular recess is formed between its periphery and the flange 21, within which the base of the cushion 14: is tightly com pressed as the bolt 24 is tightened. I prefer to form the flange 21 so that its elements form an angle with the corresponding ele- This contact surface conments of the conical face 18 which angle is substantially equal to that formed by the corresponding element of the conical periphery of the securing disk 22.

The drawing shows the polishing surfaces slightly separated opposite the dotted line ab, and this is the position which they occupy while active. The space between the cushions is then occupied by the thickness of the object being polished, which object is squeezed between the cushions 13 and 14 by action of the spring 15, or equivalent means.

The particular arrangement of the various parts as shown in the drawing is not essential to my invention, and it is not my intention to limit my claims otherwise than as expressly stated in each respectively.

What I claim is 1. In a polishingmachine, two opposed annular polishing cushions each tapering in cross section, two wheels for carrying said cushions having each an annular recess of tapering cross section for receiving the bases of said cushions, revoluble mountings for said wheels so placed as to maintain said cushions inclined to each other as a whole while coming together at a line of contact, and means for producing simultaneous revolution of said wheels, substantially as described.

ably secured near the center of each wheel adapted to secure a cushion against each pressure-resisting surface and its limiting flange, substantially as described.

8. As a mounting for the cushion of a polishing machine, a wheel having on its face an annular pressure resisting surface forming part of a flat cone whose apex 1s above sa-id face, said surface being limited.

by an external flange slightly overhanging said surface, and a securing 'disk removably secured near the center of said wheel, said.

disk having a conical periphery also "sli'g l'itly overhanging said pressure-resisting surface, substantially as described.

In testimony whereof, I aifix my signature, in presence of two witnesses.

HENRY ROBINSON.

Witnesses: s

HARRY DAVIDSON, V JOSEPH WERTZHEISER.

Copies 0! this patent may be obtained for five cents each, by addressing the Commissioner of rawm, Washington, ID. 3 

